By now it is clear that sustainable construction is not a fad but instead a major trend. The U.S. Green Building’s LEED green building rating system is referenced in dozens of laws, policies and incentives in 34 states, 138 cities and 14 Federal agencies and departments. By 2013, McGraw-Hill Construction projects that the green building market will grow to 25% of all new construction starts by value, equating to a $140 billion market.
Green construction codes and standards are beginning to emerge on the national code stage. The standards go beyond energy standards such as 90.1 and the International Energy Conservation Code (IECC) to cover additional areas such as site sustainability, water efficiency, indoor environmental quality and materials and resources.
The first is ASHRAE Standard 189.1, Standard for the Design of High-Performance, Green Buildings Except Low-Rise Residential Buildings, published by ASHRAE in January 2010 in conjunction with the USGBC and the Illuminating Engineering Society. Standard 189.1 provides criteria by which a building can be judged as “green,” written in model code language that jurisdictions can use to develop a green building construction code. It does not replace LEED, however, nor does it replace the ASHRAE’s 90.1 energy standard—instead modifying 90.1 to achieve a 30% reduction in energy cost over 90.1-2007 in addition to requiring energy measurement for verification purposes, on-site renewable energy production capacity, and capability to reduce peak electric demand.
Lighting is covered in Section 7.4.6. This section, in turn, is based on Section 9 of ASHRAE 90.1 with several significant additions and modifications to increase energy savings, including:
* Lighting power densities are capped at 90% of 90.1
* Manual-ON or bilevel automatic-ON occupancy sensors are required in <250 sq.ft. offices, all classrooms and other spaces
* Otherwise, all occupancy sensors must be manual-ON
* Occupancy sensing to switch or dim to at least 50% of power required in hallways in hotels, motels, dorms, multifamily buildings; industrial and commercial storage stacks; and library stack areas, with an exception for low-LPD HID
* Emergency lighting capped at 0.1W/sq.ft. but additional allowed if controlled by automatic shutoff device
* Daylight zones >250 sq.ft. must be automatically controlled by daylight sensing coupled with continuous dimming or stepped switching, with several exceptions
* Outdoor lighting must comply with Section 9 of 90.1 except building facades, parking lots, garages, canopies (sales and non-sales) and outdoor sales areas require automatic controls to reduce lighting power by at least 50% one hour after normal business closing and within 30 minutes after sunrise, with some exceptions
Additionally, Section 188.8.131.52 requires peak electric load reduction capability:
* Building must contain automatic systems capable of reducing peak electric demand by at least 10%, not including standby power generation
Electric lighting demand can be reduced by turning lighting off, dimming it or using it more efficiently. Because lighting is typically a critical system, many lighting systems cannot be turned off during peak demand hours. This leaves dimming it. With dimming ballasts connected to a central point of control, lighting loads can be reduced on demand.
To learn more about ASHRAE 189.1 and preview a copy of it online, click here.
The International Code Council (ICC), which publishes the IECC model energy code and other International Codes, is now working on its own green building standard, called the International Green Construction Code (IGCC). The American Institute of Architects (AIA) and ASTM International are “cooperating sponsors.” According to IC, a critical element of the IGCC is that it will be consistent and be coordinated with existing International Codes that span the industry from building and energy conservation to fire safety and plumbing.
In March, the ICC’s Sustainable Building Technology Committee, responsible for drafting the document, will publish the first public version of the IGCC. In August, additional public comments will be solicited in a series of hearings. The IGCC will then go through another around of review, comments and public hearings in 2011, with final publication targeted for the release of the 2012 ICC family of codes, including IECC 2012.
Meanwhile, California is moving ahead with its own green building code, approved on January 12, 2010 and set to become effective January 1, 2011. Called CAL Green, it will apply to all commercial and residential building construction in the State of California. Building owners will be able to label their buildings as CAL Green compliant once the building passes inspection, without the added cost of third-party certification programs.
At first, these ASHRAE and ICC standards may be used as the basis for specialty codes for public construction in the greenest parts of the country. Ultimately, however, it is highly possible that they represent the next phase of evolution of building and energy codes.